Oh another one who thinks surge marks exist. They don`t. They are simply areas that received the proper agitation compared to the areas that that did not so they are under developed.

This is what I thought surge marks were. Anyway, that's what I see with steel and it goes away with plastic. I think your right about the random agitation working.

This info wasn't on Kodak's website when I needed it --- 25 years ago.

09-07-2005, 10:04 PM

Mike-D

I believe that pinholes resulted from acid stop bath coming into contact with developer containing sodium carbonate. Kodalk was developed in the 1930s to combat this problem. Carbonate in developers is very rare now days.

That being said I have always used water stop bath. Fill the tank with water (same temp as developer and fix) agitate for 15 seconds (12 inversions for me) drain and repeat. Then into the fix. Always used stainless steel too.

Didn't even have to change my procedure when I finally did use a carbonate accelerated developer!

Mike D

09-07-2005, 10:18 PM

Ole

Quote:

Originally Posted by Mike-D

Carbonate in developers is very rare now days.

Not all that rare - two of my favorite developers (Beutler's/Neofin and Pyrocat-HD) both contain carbonate.

09-07-2005, 11:06 PM

Donald Miller

Quote:
"I believe that pinholes resulted from acid stop bath coming into contact with developer containing sodium carbonate. Kodalk was developed in the 1930s to combat this problem. Carbonate in developers is very rare now days."

To the developers containing carbonate that Ole mentioned, I would add ABC Pyro which is used fairly extensively today.

09-08-2005, 09:23 AM

Donald Qualls

Not to mention (in terms of carbonate alkalized developers) Caffenol, Diafine, and Dektol (the last not usually used for film these days, but it still works).

Is it possible that a water stop bath is less effective in stopping development at the edges of the film where it is in contact with the reels?

In a word yes!

Always use an acid stop for paper and film. It will eliminate many problems down the line after the developer and provide consistent repeatable results.

I've been processing film for over 30 years and have never seen pinholes. Just dilute the stop properly.

Don Bryant

09-08-2005, 10:46 AM

Photo Engineer

In the early days of photography, emulsions were unhardened or poorly hardened. This led to the formation of bubbles by reaction of carbonate from developer carryover to the acid in the stop bath or acid fixer. The reaction with an acid fixer can take place even with a short rinse of water.

However, first it must be said that the carbon dioxide that is formed is in very tiny amount and it dissolves rapidly in the water of the stop bath, and so when these bubbles were observed, it was usually in a deep tank process where hydrostatic pressure prevented the bubbles from being released until the film or paper approached the surface of the tank and the pressure was reduced.

The result was that the bubbles didn't show up in tray or shallow tank processes, but did sometimes in deep tank photofinishing processes. This was seldom and only seen pre-1960s.

In the 60s, most major film manufacturers switched over to hardeners that allow processing up to 100F for color films and papers and over 68F for B&W films and papers. These new products are not affected by the use of an acid stop bath in any way as far as can be determined, even in deep tanks or at high temperatures (RA color paper with a stop at 100F has no problems with pinholes and the RA and C41 developers are both carbonate based).

The only way I can generate bubbles (not pinholes) is to coat a totally unhardened emulsion at very high gelatin and then use an acid stop. I can see bubbles form before my eyes, and they don't form in the stop, they form in the acid hardener fix and can even form in the wash. They appear more like blisters.

I must add that not all manufacturers use these new modern hardeners, and therefore you might, in extreme cases, see blisters or marks from acid/carbonate interaction in such films.

I have never observed even this, but I warn you of the possibility.

I have used acid stops for film and paper for over 30 years with absolutely no problem, but have had problems of one sort or another with using a water rinse after development.

I will continue to use an acid stop.

PE

09-08-2005, 02:58 PM

Ole

I have had bubbles/blisters on EFKE rollfilm in a Paterson tank with an acid stop. I like EFKE films, and especially in "Beutler's". Reason enough for me to avoid acid stop if I can.

09-08-2005, 03:16 PM

Donald Qualls

Same is true with J&C Pro 100 -- acid stop or temperature above 68 F can lead to blisters or pinholes. Both this film and Efke are completely unhardened emulsions similar to those in general use prior to 1960.